The Ultimate Result

The ultimate purpose of creation is that all of mankind should acknowledge and appreciate that G-d created them (Ramban). The Netziv writes that G-d ordained that recognition of His presence and glory will fill the earth, as it says, "All that I created and made are for My honor" (Yeshayahu 43:7). This is the perfection of the world that will occur when Mashiach comes and history reaches its culmination. As we pray on Rosh Hashanah, "Rule over the entire world in Your glory…and let all who have a breath of life in their nostrils declare that Hashem, the G-d of Yisrael, is King and His kingdom rules over all."

The ten plagues and the Exodus from Egypt brought both the the Jewish people and the Egyptians to the knowledge that there is a G-d who is involved in the world and that He is the G-d of Israel. However, it was imperative that the world know that the very G-d of Israel was also their G-d, and that it was part of the mission of the Jewish people to bring this message to the world. The Exodus from Egypt and all the plagues preceding it showed that G-d was the G-d of the Jewish people – He saw their suffering and intervened to alleviate that suffering. However, it did not show that G-d was also the G-d of the Egyptians. Hence our redemption and recognition of Hashem was not complete until the splitting of the sea (the seventh day of Pesach), which showed that G-d was not only our G-d but the G-d of all the world – even the Egyptians.

When the Telzer Rosh Yeshiva, Rav Avraham Yitzchak Bloch was taken out to be murdered, the Nazi officer taunted him, "Rabbiner, where is your G-d now?" The Rav replied, "He is not only my G-d, but yours, too, and one day the whole world will see and understand that fact."
(Rabbi Zev Leff)